Elevator control system



y 2, 1941. M. A. MYERS 2,250,27

ELEVATOR CONTROL SYSTEM Filed Nov. 15, 1939 6 Sheets-Sheet 1 ATTO RN EYSJuly 22, 1941.

M. A. MYERS ELEVATOR CONTROL SYSTEM- Filed Nov. 15, 1959 e Sheets-Sheet2 GCR GCL TR l/7/ ercepf/bn Se/ecfor [6 II! /6 L /5 III IN V E N TO Rfiforf/merA/vyers ATTO R N EYS July 22, 1941. A, MYERS 2,250,272

ELEVATOR CONTROL SYSTEM Filed Nov. 15, 1939 6 Sheets-Sheet 4 Magnef 55INVENTOR Mort/7220A Nye/s BY %WF ATTORNEYS July '22, 1941. M. A. MYERS2,250,272

ELEVATOR CONTROL SYSTEM Filed Nov. 15, 1939 v 6 Sheets-Sheet 5 M-s Q/Z;

ATTORNEYS rection toward the first floor.

Patented July 22, 1941 UNITED STATES PATENT OFFICE ELEVATGE CONTROLSYSTEM Application November 15, 1939, Serial No. 304,572

19 Claims.

This invention relates to an elevator control system more particularlyfor use in buildings having more than two floors and in which noattendant is necessary in the elevator to control its operation, itsoperation being entirely under.,, the control of the persons using it.The elevator control system of the invention is especially adapted foruse in buildings of medium height which are frequented by a considerablenumber of people such as, for example, apartment houses,,l of from to isstories.

Elevator control systems have been proposed in which push buttons areprovided on the various floors and complicated mechanical apparatus isdisposed in the elevator shaft for causing the l starting of theelevator in response to the operation of a fioor push button and forcausing its stopping at a desired floor. It is a purpose of the presentinvention to avoid the use of complicated mechanical apparatus in theelevatorshaft and to control the elevator largely by electrical means inthe form of electrical circuits which comprise relays, switches andassociated apparatus most of which may be positioned in the same controlroom with the hoisting drum 5 and the electric motor which drives it.

It is accordingly an object of the present invention to provide anelevator control system in which the elevator will automatically startfrom one floor and automatically stop at another floor in response tothe pressing of a hall button at the latter floor. Should the car he atthe fifth floor, for example, and a hall button be pressed at the firstfloor, the car will automatically start and proceed to the first floorwhere it will automatically stop. According to a further feature of theinvention, a super interceptive system is provided which stops the carautomatically at the third floor, for example, in response to thepressing of a third fioor hall button while the car is moving downbetween the fifth and third floors. The call for the first floor is notcancelled, however, and the car is automatically started after thepassenger on the third floor has entered and proceeds in its establisheddi- It is a further object of the invention that calls are automaticallycancelled after they have been answered, so that in the example given,the car will not again return to the third floor after it has completedits trip in the established direction by stopping at the first floor.

According to another object of the invention the super interceptionsystem includes a selector device which is mechanically associated withthe elevator and is effective in preventing the car from answering acall in a direction opposite to the established direction of car travel.For instance, in the above illustrated example, the car will not respondto the pressing of a hall button, on the seventh floor after the car hasstarted in its established direction toward the first floor. Thisresults in giving control of the car to the person who initiates thefirst call. In the illustrated example, the partly desiring the car onthe seventh floor would have to press the seventh floor hall buttonafter the car had made its stop at the first floor.

Other objects of the invention wil become apparent to those skilled inthe art as the description thereof proceeds. For a better understandingof the invention, however, reference is made to the accompanyingdrawings in which,

Figs. 1, 2, 3 and 4 represent diagrammatically an elevator controlsystem embodying my invention and,

Figs. 5 and 6 represent diagrammatically an alternative modification ofthat portion of the system shown in Figs. 1 and 2.

Referring first to Figs. 1 to l, the control system embodying theinvention is shown associated with an elevator car i which drives astopping selector shaft 2 by means of a flexible drive memberillustrated as a chain 3 which passes around a sprocket wheel 4 securedto the shaft 2. The shaft 2 thus rotates in timed relation with theelevator car i and carries a series of stopping selector cams 5, 5", 5"and 5" for controlling the stopping of the car at the first, second,third and fourth floors respectively of the building. These cams operatethe levers 6 through the friction rollers l, the levers 6 serving toopen and close a circuit through the upper pairs of contacts 8, 8", 8"and 8 and the rollers 7 serving also to operate the movable switchblades 9, 9", 9" and 9"" which cooperate with the fixed contacts I0,it", ill and 2" respectively. The shaft 2 drives a second selector shaftH by means of the sprockets I2 and I3 which are connected by a sprocketchain l4. Shaft II carries a series of interception selector cams l5,i5, 15, |5"" which operate the movable switch blades l 6, I6", l6 and l6which cooperate with the pairs of left and right switch contacts, ll,"3, ll", [8", ll, iii and Il"", l8 respectively. Shaft H also carries aseries of direction selector cams l9, [9", IS' and la which operate themovable switch blades 20, 23", 29 and 251" which cooperate with thepairs of left and right switch contacts 2|, 22; 2!, 22"; 2F, 22" andZl",

22 respectively. The elevator motor 23 equipped with a brake magnet 24of the usual type is provided with the usual type of driving connection(not shown) to the elevator l and is adapted to be supplied with powerfrom the three pha-e power lines Li, L2, L3 through the circuitshereafter described. Hail push buttons 25, 25',

w and at the first, second, third and fourth doors respectively of thebuilding are shown a s 'lar series of push buttons 25", and 2 areprovided in the car I.

The remaining elements of the system may be best described in connectionwith the operation or" the car which is shown stopped at the third floorin Pig. 3. Upon a person on the first floor wishing to use the car, hepushes the first floor hall button which establishes circuit #1extending iroin through lead 23, movable contact 29 of a stopping relaySR, lead 30 which is common to the car push buttons 26, 26" etc., hallpush button cut-out switch 3i, hall push buttons 25, etc., lead 32,contact l8, switch blade [6, lead 33, first floor relay FRi, resistor Biand lead 2? to Li. The completion of this circuit causes the relay PM tobe energized and to close, thereby establishing circuit #2. The stoppingrelay SR and a similar relay SR! are each provided with a dash potdevice 34, 34 to cause a suitable time clay in the return of the relayarinatures after the interruption of the current through their windings.

Circuit #2 connects L2 to Li through lead 28, movable relay contact 29,lead 35, lower contact 36 of relay FRi, coil of relay FRI, and RI. Theclosure of this circuit causes current to be bypassed around theinterception selector contact i8 and hall push button 25 and the floorrelay FRI sustains without continuing the pressure on the push button25. The completion of circuit #2 and operation of floor relay FRIestablishes circuit #3 which connects L2 to Ll through lead 28,auxiliary contact 31 of the up relay UR, coil of down relay DR, downcontact 2| of direction selector switch 20, and upper contact 38 offloor relay FRI. The result of the completion of this circuit is thatthe down directional relay DR closes and sustains thereby establishingcircuit #4. Circuit #4 connects L2 to Ll through lead 28, emergency stopbutton SB which is located in an accessible place in the car I, hatchwaydoor contacts 40, 40", 43" and 49", contact 41 of stopping relay SR1,lead 42, top contact 43 of down relay DR, lead 44, coil of gate pilotrelay GP, lead 25, and movable contact 46 of a time relay TR which isprovided with a dash pot device 47 of any suitable type and anenergizing winding 48. The result of the passage of current throughcircuit is the closure and sustaining of the gate pilot relay GP and theestablishing of circuit #5.

Circuit comprises L2, lead 28, top contact 49 of gate pilot relay GP,the coil of car gate closing relay GCRfthe car gate closing limit switchGCL, lead 27 and LI. Passage of current through this circuit causes thegate closing relay to operate, thereby establishing a circuit (notshown) for the car gate motor which closes the gate of the car. Theclosure of the car gate automatically closes the switch contact 50 whichis mechanically associated with the gate and also raises a door lockretiring cam 5| carried on the car which in turn closes the switchcontact 52" and establishes the door lock circuit. This causes theestablishing of circuit #6 which comprises L2, lead 28, stop button SB,hatchway door contacts' 43 to 45, relay contact 4|, car gate switchcontact 50, lead 53, down stopping limit switch DS, auxiliary switchcontact 54 of the up switch U, the coil of down switch D, lead 55,contact 43" of relay DR, lead 56, hatchway door contacts 52 to lead 5'1,lower gate pilot contact 49", lead 21 and LI. The passage of currentthrough the coil of down switch D causes this switch to pull in andestablish circuit #7.

Circuit #1 comprises L2, lead 28, stop button SB, hatchway door contacts46 to 46", relay contact 4i, car gate contact 55, lead 39, mainpotential switch coil P, lead 58, lower auxiliary contact 59 of downswitch D, lead 55, third contact 43 of direction relay DR, lead 56, doorlock switches 52 to 52, lead 51, third contact 49 of GP, lead 27 and LI.The result of the closure or" this circuit is ie operation of mainpotential switch P, and the connection of the terminals T3, T2 of motor23 to the mains L2 and L3 through the circuit comprising lead 28, lowercontact 60 of switch P, lead 6i, lower main contact 62 of down switch D,lead 63, lead 84, upper switch contact 62, and lead 55. Motor terminalTl is simultaneously connected to supply main Ll through the circuitshown including the lead 21 and switch contact 65. The current throughthe motor causes it to rotate so as to move the car in the downdirection, as desired. It will be noted that the closing of down switchD caused the circuit including lead 66 and the coil of the up motionswitch U to be broken at the upper witch contact 59', thus preventingthe operation of the switch U which controls the motion of the car in anupward direction and thereby providing an electric interlock. It willalso be noted that the circuit through the UR coil is broken at thecontact 3'! of DR and thus prevents the car from responding to a call inthe opposite direction to its established direction of travel asdetermined by the first call.

The next circuit established is #8, the stopping circuit. It will benoted that all the interception selector contacts [8, l8" and l8 areshown to the right the only one being shown to the left being that one,IT, for the third floor at which the car is located. This means that thecams 5 to l5" are so arranged that the only time an interceptionselector switch blade, 16 to 16, is thrown to the left is when the caris located at a particular floor either idle or moving. Thus when thecar arrives at its destination, in this case the first floor, cam l5throws switch blade Hi to the left into engagement with contact l1thereby establishing circuit #8 which comprises L2, lead 28, stoppingrelay contact 29, lead 35, floor relay contact 36, lead 33, switch bladel6, contact l1, first floor stopping selector switch contacts 8, lead58, coil of stopping relay SRl, lead 21 and Li. This circuit is notbroken by movement of SR contact 29 but the closure of this circuitcauses the armature and contact 4| of relay SRI to pull in and compressa spring in the dashpot device 34. When the car arrives in position forcam 5 to engage roller 1 and operate switch lever 6 to break the circuitat switch contacts 8, the coil of relay SR! is deenergized and contact4| opens momentarily. We have seen that contact 41 is included incircuit #4, the gate pilot coil circuit, also in circuit #6 whichincludes the coil of down switch D and also in circuit #7 which includesthe coil of potential switch P. Therefore, the opening of relay contact41 interrupts the flow of current in these three circuits which causesthe down switch D to drop out, and the potential switch P to drop outthereby breaking the energizing circuit of motor 23 and the stopping ofthe car. The gate pilot relay GP has also dropped back establishing anauxiliary circuit #9 which comprises L2, lead 28, auxiliary contact 6?of the relay GP, GOR, coil, gate opening limit switch, lead 27 and Li.Passage of current through this circuit causes the gate opening relayGOR to pull in, which in turn establishes a reverse circuit through thegate opening motor (not shown) which automatically opens the car gateand per mits the passenger to enter or exit.

If an intercepting call for the second floor were registered by a partypressing the hall push button 25" before the car arrived at this floor,as the car arrived in the proper stop} ing position for the secondfloor, the second floor intercepting selector switch it will be pushedto the left by cam IE3" establishing a circuit to Ll through contactll", stopping selector contacts 3", lead (it, coil of SRi and lead ill.Then when the cam 53 engages roller 7 and operates swi' ch 3 to open thecircuit at switch contacts 8" the current is interrupted through thecoil of S'Ri and the car comes to a stop at the second floor and the cardoor is also automatically opened by its motor, in the same manner asabove described.

In this arrangement the floor relays are dropped. out in succession inthe order that the calls are answered. In the example given, when thecar stops at the second floor the cam in raising roller 1 to open switchcontact 8 has also raised switch blade 9 closing contact it. A circuitis thus formed from the top of PR2 coil, lead "J3, switch blade it",contact ll, contact It", contact 9", lead 732 to bottom of PR2 coil.Since there is no potential difierence across its coil terminals, therelay FR 2 drops out, thereby cancelling the call for the second floor.A short circuit to LI is prevented by the insertion of the resistors Rt,R2, and Ed in series with the coils of the floor relays F ti to PR5.However, the original call for the first floor has not been cancelled orotherwise disturbed as neither contacts 8" nor ii are in the circuitwhich registers the first floor call. We have seen in #4 circuit thattime relay contact 46 is in series with the coil of the gate pilot relayGP. As the time relay coil winding $8 is energized by current passingthrough the leads 88, '50 all the time the car is running, relay contacti6 is open during this time, the gate pilot coil relay in the meantimebeing sustained by current from Ll passing through lead 27, the middlecontact 1%" of the GP relay and lead t4. Upon the car stopping and theinterruption of current to the time relay coil Bil by the opening ofcontacts iii 36' of the switch P, contact 26 closes after a timeinterval because of the action of dashpot device ill. During thisinterval, the passenger has time to enter or leave the car at the secondfloor landing and after contact at is again made, the gate pilot coil GPis again energized since the first floor call still remains, causing thearmature of GP to pull in and reestablish circuits #6 and #7, causingthe car gate to close in the manner above described and allowing the carto proceed to the first floor. The coil of SR is energized through acircuit comprising Ll, lead ll, contact 53 or 54, SR coil, lead 28 andL2. The contact 29 is thus pulled in but not broken, similar to theaction of SR previously described, as long as either DR or UR isenergized, which is to say, as long as a direction of travel isestablished. As soon as the last call in the established direction isanswered, and the DR or UR coil drops out, SR contact 25 is momentarilyopened cancelling any calls that may have come in for the oppositedirection of travel leaving the elevator control system free to answer anew call or series of calls.

It is thus seen that the control system described causes the car to stopautomatically at the floors in their natural order at which floor pushbuttons are operated and that the calls are cancelled after the stopsare made. It will also be seen that the up and down relays UR and DR areso interconnected that only one may be energized at a time so that afterthe direction of the car motion has once been established by the firstcall entered, the car will not answer to any call in the oppositedirection. The switches US and DS are safety switches disposed in thehatchway above the level of the top floor and below the level or thebottom floor landings, respectively, and are operated by a cam (notshown) fixed to the car in order to limit its ward and downward motion.

It will be readily understood from the foregoing that in respondlug toan upper floor button from a car position on the first floor, circuitssimilar to those above described will be established through the uprelay UR instead of the down relay DR and through the up switch Ucontacts 5 1, H, H instead of the corresponding contacts of down switchD. The establishment of these circuits causes the motor 23 to be soenergized as to cause the car to travel in the desired upward direction.

The modified form of control system shown in Figs. 3, 4, 5 and 6 isgenerally similar to that above described and parts in Figs. 5 and 6which correspond with similar parts in Figs. 1 and 2 are indicated bythe same reference characters. In this form or the invention theresistors Rl to R4 (Fig. l) in series with the windings of the floorrelays FBI to PR6 are omitted as are also the extra contacts ill to iii"on the stopping selector switches 5. With the car at the third floor, acall entered for the first floor and an interceptive call for the secondfioor, the car starts downward with both FEE and F82 relays closed andsustained and the down relay DR closed and sustained as above describedin connection with circuits #1, #2 and #3. The coil of stopping relay SRis connected as heretofore described with movable switch contacts 43 ofdirection relay DR and contact i i of direction relay UR, and the relaySR remains unaffected as long as a direction relay DR or UR remainsclosed. Circuits l, #5 and #6 are also closed and sustained asheretofore described. When the car arrives in juxtaposition to thesecond floor, cam 5" operates switch 6 to open the switch contacts 8thereby interrupting the current through lead 68 and the coil of S'Ri,thus releasing this relay. This interrupts the current through contactll momentarily and drops off down switch D and potential switch P, thuscutting off current to the motor 23 and stopping the car at the secondfloor. lhe momentary opening of relay SR! also drops out the gate pilotrelay GP since the circuit including lead 4 and the coil of this relayis broken at contact ll. The release of GP relay initiates the car gateopening, time delay and car gate reclosing, as above described. As thefirst floor tablished direction of car travel was upward,

down relay DR cannot close as long as up relay UR remains closed, sinceits coil is connected in series with open contact 31 of the up relay.

SR! contact 61 having closed immediately after its momentary opening,causes down switch D j and potential switch P to close after thestopping cycle is completed and the car continues downward to completeits call at the first floor landing.

Having answered the last call in the established direction, cam l9permits switch 20 to move to the right and break the circuit includingcontact 2| supplying current to the coil of relay DR causing this relayto open. This breaks the circuit which supplies current to the coil ofSR relay at relay contact 43 and causes the movable contact 29 of relaySR to open momentarily due to the dashpot action. The opening of thiscontact breaks the circuit including leads 35 and 28 which suppliescurrent to the coils of all the fioor relays FBI to FEM causing all thefloor relays to release simultaneously and thus cancel all the callsthat have been answered also any calls that may have come in for theopposite direction of travel. swered all calls in the establisheddirection of travel in their proper order, the control circuits are nowin their initial condition and the elevator is ready to respond to newcalls. This system is entirely similar to the first described system,diiiering only in that the floor relays FRI to PR4 are not deenergizedas soon as the car arrives at a particular floor, but only after thelast call in the established direction is answered, when they are alldeenergized together. While the invention has been illustrated asapplied to a building having four stories for the sake of simplicity, itwill be understood that it is adapted for buildings having a lesser orgreater number of floors.

I have described what I believe to be the best embodiments of myinvention. I do not wish, however, to be confined to the embodimentsshown, but what I desire to cover by Letters Patent is set forth in theappended claims.

I claim:

1. A super interceptive system for controlling an elevator carcomprising, in combination, a plurality of iioor relays, one for each ofa plurality of floors, means including a switch at each floor foroperating said relays, means controlled by said relays for operating thecar in an established direction, stopping and automatically starting thecar at the floors at which switches are operated, in the natural orderof floors, regardless of the order in which said switches are operated,said controlled means being arranged to prevent the starting of the carin a direction opposite to the established direction in response to theoperation of a floor switch after the starting of the car, andcomprising a stopping relay and a circuit for supplying energizingcurrents to the coils of the floor relays of suflicient strength as tocause the operation of a plurality of said relays in response to theoperation of a Having anr plurality of said floor switches, said circuitincluding a switch operated by the stopping relay.

2. A super interceptive control system as set forth in claim 1 in whichthe coils of the floor relays are connected in parallel with each otherand in series with said stopping relay switch whereby the opening ofsaid stopping relay switch is adapted to interrupt the current to thecoil of any of the floor relays.

3. A super interceptive system for controlling an elevator carcomprising, in combination, a plurality of floor relays, one for each ofa plurality of floors, means including a switch at each floor foroperating said relays, means controlled by said relays for operating thecar in an established direction, stopping and automatically starting thecar at the floors at which switches are operated, in the natural orderof floors, regardless of the order in which said switches are operated,said controlled means being arranged to prevent the starting of the carin a direction opposite to the established direction in response to theoperation of a floor switch alter the starting of the car, andcomprising two stopping relays, a switch operated by one of the stoppingrelays and arranged to deenergize all of the floor relays, a secondswitch arranged to control the movement of the car and means for movingthe second switch in response to the operation of the other stoppingrelay.

4:. A super interceptive system for controlling an elevator carcomprising, in combination, a plurality of floor relays, one for each ofa plurality of floors, means including a switch at each floor foroperating said relays, means controlled by said relays for operating thecar in an established direction, stopping and automatically starting thecar at the floors at which switches are operated, in the natural orderof floors, regardless of the order in which said switches are operated,said controlled means being arranged to prevent the starting of the carin a direction opposite to the established direction in response to theoperation of a floor switch after the starting of the car, andcomprising a plurality of cams mechanically connected to the car, onefor each floor, and means whereby said cams cause the floor relays tobecome successively deenergized in response to the successivepositioning of the car at the corresponding floors.

5. The combination as set forth in claim 4 in which the last named meanscomprises a plurality of control circuits adapted to connect theopposite terminals of the relays, each of said control circuitsincluding a switch adapted to be operated by one of said cams.

6. The combination as set forth in claim 4 in which resistors areconnected to one terminal of the floor relays, the outer ends of saidresistors being continuously connected to a source of potential supply.

'7. A super interceptive system for controlling an elevator carcomprising, in combination, a plurality of floor relays, one for each ofa plurality of floors, means including a switch at each floor foroperating said relays, means controlled by said relays for operating thecar in an established direction, stopping and automatically starting thecar at the floors at which switches are operated, in the natural orderof floors, regardless of the order in which said switches are operated,said controlled means being arranged to prevent the starting of the carin a direction opposite to the established direction in response to theoperation of a floor switch after the starting of the car, andcomprising a directional relay, a directional switch coil, a potentialswitch coil, a stopping relay having its switch contact connected inseries with said directional and potential switch coils and a source ofpotential, a plurality of stopping selector switches connected to thecoil of said stopping relay, a plurality of cams mechanically connectedto the car and arranged to successively operate said stopping selectorswitches, a second stopping relay having its coil connected in serieswith the contact of said directional relay and having its contactconnected in series with the contact arms of the floor relays.

8. A super interceptive system for controlling an elevator carcomprising, in combination, a plurality of floor relays, one for each ofa plurality of floors, means including a switch at each floor foroperating said relays, means controlled by said relays for operating thecar in an established direction, stopping and automatically starting thecar at the floors at which switches are operated, in the natural orderof floors, regardless of the order in which said switches are operated,said controlled means being arranged to prevent the starting of the carin a direction opposite to the established direction in response to theoperation of a floor switch after the starting of the car, andcomprising a. rotatable shaft, means for rotating said shaft through anangle proportional to the movement of the car, a plurality of camssecured to said shaft, one for each floor, a plurality of switch bladesarranged to be successively actuated by said cams in response to thesuccessive positioning of the car at the corresponding floors andcircuits connecting said switch blades to the opposite terminals of thefloor relays whereby the closure of said switch blades causes theopposite terminals of the fioor relays to assume the same potential,thereby releasing said relays.

9. A super interceptive system for controlling an elevator carcomprising, in combination, a plurality of floor relays, one for each ofa plurality of floors, means including a switch at each floor foroperating said relays, means controlled by said relays for operating thecar in an established direction, stopping and automatically starting thecar at the floors at which switches are operated, in the natural orderof floors, re-

gardless of the order in which said switches are operated, saidcontrolled means comprising a plurality of cam operated switch devicesarranged to short circuit the windings of the floor relays successivelyin response to the positioning of the car at the corresponding floors.

10. A super interceptive system for controlling an elevator carcomprising, in combination, a plurality of floor relays, one for each ofa plurality of floors, means including a switch at each floor foroperating said relays, means controlled by said relays for operating thecar in an established direction, stopping and automatically starting thecar at the floors at which switches are operated, in the natural orderof floors, regardless of the order in which said switches are operated,said controlled means being arranged to prevent the starting of the carin a direction opposite to the established direction in response to theoperation of a floor switch after the starting of the car, andcomprising a stopping relay having a movable contact, a directionalrelay having a movable contact, an energizing circuit arranged toconnect the contact of the directional relay in series with the coil ofthe stopping relay and a circuit arranged to simultaneously energize andhold a plurality of the floor relays, said circuit having the movablecontact of the stopping relay in series therewith, and means formaintaining the directional relay energized until the car has arrived atthe last floor in the established direction and for deenergizing saiddirectional relay at said last floor, whereby the release of thedirectional and stopping relays causes the floor relays to besimultaneously released.

MORTIMER A. MYERS.

